This invention relates to one of the treatment methods for gastric and esophageal varices resulting from a liver disease. The invention relates to an endoscopic ligation kit used in a ligation operation in which a varix is ligated to thereby mechanically shut off a blood circulation so as to reduce, extinguish or thrombose the varix.
A mainstream treatment for gastric and esophageal varices due to liver cirrhosis or the like has heretofore been an endoscopic injection Sclerotherapy (EIS) in which an indurating agent, having a blood-coagulating nature, is injected into the varix or a portion outside the varix, and thus effecting treatment.
However, the perivenous administration of the medicine, having side effects on the living body, has caused various complications, such as a pulmonary embolism, and pulmonary failure and kidney disorder, in combination with complicated blood circulation kinetics of a portal hypertension. Therefore, a dose of the indurating agent is limited, and the treatment is carried out, taking the recovery of the patient into consideration, and therefore there has been encountered a problem that the treatment time is prolonged.
Recently, an esophageal varices ligation (EVL) has been used as a treatment method for gastric and esophageal varices. As shown in FIG. 7, EVL is a technique in which a varix 14 is drawn into a tubular device 11 mounted on a distal end of an endoscope 6, and an O-ring 4, beforehand expanded and fitted on an outer periphery of a cylinder 12, is disengaged from this cylinder by pulling the cylinder 12 by means of a wire inserted through a biopsy channel, and is fitted on a proximal end portion of the varix 14 drawn into a polyp-like shape, and the varix is mechanically ligated by a contracting force of rubber of the O-ring, thereby devastating the varix.
A currently-used ligation kit will now be described with reference to the drawings. FIG. 6B shows the construction of a ligation kit now extensively used, and tubular device 11, mounted on a distal end of an endoscope 6, comprising an endoscope mounting portion 7, an outer tube 3, and a cylinder 12 having an O-ring 4 mounted on a distal end portion thereof, a wire 13, passed through the biopsy channel 9 in the endoscope, is beforehand connected to the cylinder 12, and when the wire 13 is pulled, the cylinder 12 is retracted, so that the O-ring 4 is pushed by the outer tube, and is disengaged from the cylinder 12.
FIG. 6A shows a pneumatically-driven ligation kit having a principle difference from that of FIG. 6B. In this method, a slide cylinder 2 is provided between an inner cylinder 1 and an outer cylinder 3, and a fluid is fed under pressure from a syringe 10 via a connector 8 and a tract tube 5, and causes the slide cylinder 2 to be projected so as to disengage the O-ring 4, thereby ligating a varix. In the EVL using such an endoscopic ligation kit, it is not necessary to use a large amount of an induration agent as in the conventional EIS, and this is a highly-safe treatment method having little side effects on the patient, and besides any particularly difficult technique is not required when effecting the treatment, and the ligating treatment can be carried out safely with a simple operation, and therefore the number of facilities, adopting this treatment method, has been abruptly increasing.
However, in either of the devices, the endoscope must be withdrawn each time one ligation is effected, and then another O-ring must be set in position, and therefore much time has been required for inserting and withdrawing the endoscope.
A guide tube is kept in the pharynx so as to facilitate the insertion and withdrawal of the endoscope, and when withdrawing the endoscope after the ligation, the device, mounted on the distal end of the endoscope, is, in some cases, caught by a distal end of the guide tube, and is disengaged from the endoscope. In this case, the device, remaining in the body, is withdrawn by inserting a withdrawing forceps through the biopsy channel in the endoscope, and during this time, the treatment is interrupted. Furthermore, when inserting the guide tube, the mucosa is, in some cases, may be damaged by the distal end of the guide tube. As a result, a type of device which is capable of successively effecting ligations and does not use a guide tube, has been desired in the market.
In order to overcome the problem of the conventional endoscopic ligation kits that the endoscope must be withdrawn each time one ligation is effected, and before another O-ring can be attached, the present invention has been studied in various ways, and an object thereof is to provide an endoscopic ligation kit which is capable of successively effecting ligations safely and positively.
There is provided an endoscopic ligation kit for attachment to a distal end of an endoscope so as to draw and ligate a tissue in a body cavity, such as gastric and esophageal varices, characterized in that the kit comprises an inner cylinder which has a rib at an outer periphery of its rear end portion, an outer cylinder which has at least two steps of diminishing outer radii formed on an outer periphery of its distal end portion and has at least one notch extending from its distal end to its maximum outer diameter portion, and a slide cylinder which has at least one projection at its distal end portion and has a seal ring fixedly secured to its rear end portion, the projection conforms in size to the notch in the outer cylinder and has steps, the slide cylinder is received in the bore of the outer cylinder in such a manner that the projection of the slide cylinder is fitted in the notch in the outer cylinder, the inner cylinder is inserted into a bore of the slide cylinder, so that the outer cylinder and the inner cylinder are integrally connected together through the rib of the inner cylinder, this assembly is mounted on a distal end of a mounting tube and O-rings are mounted respectively on the outer periphery of the distal end portion of the inner cylinder and the step portions of the outer cylinder, an annular hermetic space is formed at a rear side of the seal ring by the seal ring, fixedly secured to the rare end of the slide cylinder, the outer cylinder and the inner cylinder, and the projection, formed on the slide cylinder, is projected forwardly by a fluid, inserted through a tube connected to a small hole in a rear end of the annular hermetic space, and disengages the O-ring, mounted on the outer periphery of the distal end portion of the inner cylinder, therefrom, and also moves the O-rings, mounted respectively on the step portions of the outer cylinder, to the forwardly-adjacent step portions, respectively.
In the above endoscopic ligation kit, a spring is provided on a distal end side of a space in which the slide cylinder can slide, and the slide cylinder, after being projected, is returned by the spring.